#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<math.h>
int main()
{
	double n = 0, m = 0 ;
	while (scanf("%lf%lf", &n, &m) == 2)
	{
		double num = 0;
		double temp = n;
		for (int i = 0; i < m; i++)
		{
			num += temp;
			temp = sqrt(temp);
		}
		printf("%.2lf\n", num);
	}
	
	return 0;
}